[BUGFIX] Check hidden state in migration

Change-Id: I0bf3be1e045a89a13c208cac57496b2fe7c52d7c
Reviewed-on: http://review.typo3.org/35309
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>